Black coated roundwound strings

Does anyone remember a certain brand of strings manufactured in the late 70's-early 80's that were roundwound, but coated with a black substance? I remember using them back then, but I've long since forgotten what brand they were.

Yes, there were a couple of different brands I believe. One was made by Kaman and were teflon coated but I never tried these. The other was made by Rotosound and were called "Spacers". These were stainless steel roundwounds that were black anodised and had different colored silks at the ends of each string. I used about 6 sets of these in the early 90's. Eventually they were discontinued. The Black Diamond string company is supposedly making a black coated roundwound bass string that will be available soon. They already make black coated acoustic and electric guitar strings.